J.M. Darrieus originally designed a wind turbine having turbine blades, disposed about a vertical axis of rotation, that interact with external fluid flow to produce torque. The Darrieus wind turbine included a flying, curved blade mounted at the top and bottom of a vertical axle. Darrieus describes a myriad of vertical blade arrangements. In a variation of the original Darrieus designs and blade arrangements, vertically-oriented troposkein blades, having a central axis of rotation, have been built and used, e.g., in the Gaspé Peninsula, Quebec, Canada.
According to numerous use examples, classical Darrieus systems have never been able to compete in scale with propeller-type, horizontal axis wind turbines, which typically are more complex and expensive to build. Indeed, many wind turbines have been dismounted due to failures. Alternative devices have not been able to solve problems of energy conversion, start up, durability, and material inefficiencies.